[1]. Field of the Invention
The present invention relates to a stopper with a damper which causes a moving object to collide with a damper and stop in a buffered manner.
[2]. Description of the Related Art
In automatic machines for processing and assembly of a work, a linear actuator described in, for example, the Patent Document, Japanese Unexamined Patent Application Publication No. 10-61611, is generally used as a conveyor means for the work. The linear actuator includes a base which incorporates an air cylinder mechanism, and a table which reciprocates linearly on the base. The table is connected to the air cylinder mechanism. As the table is driven to reciprocate by the air cylinder mechanism, the work is conveyed by the table.
The linear actuator includes a stopper with a damper to stop the table in a buffered manner at a stroke end. As illustrated in FIG. 8, this stopper 30 includes a damper hole 32 formed inside a cylindrical body 31 which is provided with an external thread 31a on its outer periphery. A damper 33 made of rubber is received in the damper hole 32 with a front end thereof protruding outward. The body 31 is screwed into a screw hole 34a of an attachment section 34 provided on a side surface of the base, and is fixed to the attachment section 34 with a nut which is screwed on the body 31.
The damper 33 is compressed when a stop block 35 fixed to a side surface of the table is caused to collide with the damper 33. Motion energy of the table is absorbed by elasticity of the compressed damper 33.
The related art stopper, however, absorbs the motion energy of a moving object only by elasticity upon compression of the damper 33. Thus, an energy absorption amount is small and shock-absorbing property is insufficient. In addition, the damper easily becomes inelastic when the damper is repeatedly extended and contracted. Thus, durability is also insufficient.